Why does this girl only flirt with me when her friend isn’t around?

[mustang1998]

So this girls friend used to like me and will only flirt with me when her friend isn’t around? Why would she do this?

[TsundereMatrix]

The only reason I can think of is the friend also likes you and this girl doesn’t want to cause drama with her friend over you.

[Yoursweetgirl]

She obviously doesn't want to flirt with you in front of her friend because they both like you. In case you don't flirt back or it doesn't go as planned, she avoids unnecessary drama from her friend's side too

[Nikki1989]

Even if her friend used to like you, there is a very high chance that residual feelings, awkwardness, or loyalty are still at play.

[beenherebefore]

Maybe she's uncomfortable in acting that way in front of her friend.

[In_Trance]

Ask her why